The purpose of this invention is to improve the vehicle heat transfer capabilities of a heat exchanger, while simplifying the production methods and costs, and reducing the part size and weight.
These are all major advantages over the prior technologies. Additionally, this invention does not require the heat exchanger to be orientation- or location-specific for vehicle applications. Prior technology requires the heat exchanger in a vehicle to be substantially in the vertical plane and located in an air stream to affect a transfer.
The vehicle heat exchangers are cross-flow designs with the fluids transported in bulk fashion through tubes, single cavity tube or with microchannels with external fins for air cooling such as a vehicle radiator and condenser. The fluids flow is typically arranged in a cross-flow design. For liquid-to-liquid heat exchangers, shell-and-tube, plate-fin or concentric heat exchangers are used.
In this invention, fluid-to-fluid heat exchangers for automotive applications are designed such that the fluids flow through microchannels in alternate and opposite (counter-flow) directions. Any number of fluids can be cooled or heated simultaneously with either a single coolant, such as a water-glycol mixture, or multiple coolants.
The heat exchanger is designed as an extrusion with microchannels with alternate channels dimensions optimized for the given fluid. A certain length of this extruded tube is then cut off and its ends crimped shut so that channels inside are fully enclosed. Next, fluid entrance and exit holes are drilled into the tube walls in a predetermined manner. Finally, manifolds are brazed on the tube walls such that they communicate with alternate channels within the extruded tube.
Other general and more specific aspects of the invention will be set forth in the ensuing description and claims.